He has starred in several television series spanning a career of more than five decades. These included his roles as Bret Maverick, in the popular 1950s western-comedy series, Maverick; Jim Rockford, in the popular 1970s detective drama, The Rockford Files; and the father of Katey Sagal's character on 8 Simple Rules following the death of John Ritter.

He has starred in dozens of movies, including The Great Escape (1963) with Steve McQueen; Paddy Chayefsky's The Americanization of Emily (1964) and Blake Edwards' Victor Victoria (1982), both with Julie Andrews; and Murphy's Romance (1985) with Sally Field, for which he received an Academy Award nomination.